Choosing the right infill structure for 3D printing

In 3D printing, creating hollow objects is a common practice to reduce material usage, shorten printing time, and achieve specific design goals. One of the most critical elements when hollowing out 3D printing is the infill structure, which determines the strength, weight, and durability of the finished print. In this article, we will explore what infill structure is and how to choose the right infill density and pattern.

What is infill structure in 3D printing?

Infill refers to the material inside a 3D printed object that provides structural integrity. Unlike the shell (walls or perimeter), infill is the "filling" inside the print. For hollow 3D printing, the infill provides internal support, ensuring that your print will not crack or warp under normal use.

Infill patterns are usually designed to be lightweight, and choosing the right infill percentage and pattern can help minimize material waste, saving time and money on printing, while maintaining enough strength to support the object.

How to choose the right infill density

Infill density is usually expressed as a percentage, ranging from 0% (completely hollow) to 100% (completely solid), and below we will explore several common infill density options.

Source: https://www.cytron.io/tutorial/a-simple-guide-to-infill-in-3d-printing

1. Low-density filling (0%-20%): Save materials, suitable for display and prototypes

For some printed objects that do not need to withstand excessive force or pressure, low-density filling (such as 0%-20%) is a good choice. This filling density can significantly reduce the use of materials and shorten printing time while maintaining the basic shape of the printed object. Common applications include display models, concept prototypes, toys, etc. Such objects are mainly used to show the appearance and have low structural strength requirements.

2. Medium-density filling (20%-50%): balance strength and save materials

Medium-density filling (such as 20%-50%) is usually used for objects that require a certain strength but do not withstand extreme loads. This density is suitable for daily use items, tool handles, models, etc., which can provide sufficient support without wasting too much material. Appropriate filling density can also maintain good physical properties without significantly increasing printing time.

3. High-density filling (50%-100%): Enhanced strength, suitable for load-bearing or functional parts

For 3D printed parts that need to withstand high pressure or frequent use, such as mechanical parts, tools, brackets, etc., high-density filling (50%-100%) is the most suitable choice. A higher filling density means that the interior is almost completely filled with material, so the printed object will be stronger and more durable. Common applications include industrial parts, mechanical gears, medical equipment components, etc.

4. Special applications (such as lightweight design): Flexible adjustment

For some applications with strict weight requirements, low-density filling can be combined with thickening the outer layer to form a lightweight design. This method is often used in aerospace, model making and other fields, which can reduce the total weight of the printed object without sacrificing the overall appearance and structure of the object. By choosing the appropriate filling density and number of shell layers, designers can flexibly adjust the weight and strength of the 3D printed object.

Types of filling patterns for 3D printing

The filling pattern affects the strength and printing time. For beautiful prints, low-density patterns such as grids or honeycombs are usually sufficient. For functional parts that require extra strength, it is best to use a higher density cube or octet pattern. Some of the most popular patterns include:

1. Grid Infill: The most common and simple infill pattern, it forms a grid structure in a staggered manner horizontally and vertically. This infill method provides good support and is suitable for most models used in daily life, especially when the printed object does not need to withstand excessive external forces. The advantage of the grid infill structure is that it prints quickly and is suitable for display models and prototypes.

Source: https://bigrep.com/posts/gyroid-infill-3d-printing/

2. Honeycomb Infill: The structure shape is similar to a honeycomb, which is a lightweight and high-strength infill method. Due to the high structural efficiency of the honeycomb structure, it can provide good strength while keeping the material usage low. Suitable for printed objects that need to balance strength and weight, such as displays, tools, and some functional parts.

3. Cube Infill: A 3D three-dimensional grid structure that provides more uniform strength than grid and honeycomb structures. It is suitable for objects that require higher strength, such as mechanical parts or functional parts. The cube infill mode usually increases printing time, but can significantly improve the durability of the printed object.

4. Triangle Infill: Use equilateral triangles to connect to form a strong structure. The advantage of this filling pattern is that it provides uniform strength and low material consumption, especially suitable for objects that are subjected to uniform pressure. Triangular filling is more stable than mesh filling and is suitable for applications that require a certain strength.

5. Octet Infill: A structure composed of octahedrons, which is a more complex but structurally efficient filling pattern. It provides stronger support and durability, especially for objects of larger size or that need to withstand high-intensity loads. The advantage of octahedral filling is that it can maintain high strength at a lower density, which is suitable for industrial parts or functional components.

Conclusion

The filling structure is an important consideration when 3D printing parts. The right filling pattern and density can ensure that your prints are strong, durable and lightweight, while optimizing material usage and printing time. Whether you are making decorations, prototypes or functional parts, understanding how to effectively design and select fillers will have a significant impact on your printing results.

JLC3DP provides a variety of services and support to help you optimize your 3D printing process. Whether you need a rapid prototype or a high-precision functional part, JLC3DP's 3D printing solutions can provide tailored support based on your specific needs to help you achieve your design goals efficiently.